• 제목/요약/키워드: Concrete construction

검색결과 8,307건 처리시간 0.036초

콘크리트포장 시공실태 조사에 따른 표준시장단가 개정 연구 (A Study on the Revision of Construction Standard Unit Price for Concrete Pavement Works)

  • 이주현;백승호
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 봄 학술논문 발표대회
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    • pp.196-197
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    • 2022
  • This study aims to come up with the revision of construction standard unit price for concrete pavement works to improve its applicability and availability by a construction site survey. Construction site survey was conducted from March to November 2021 with 36 construction sites. This results of the revision are expected to support to public construction project owner or estimator in construction cost estimation works.

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수입용 철근 및 시멘트를 사용한 콘크리트의 강도 조사 연구 (A Study on the intensity of the concrete which is made out of the steel bar and cement which is imported from foreign.)

  • 이리형;정헌수;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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    • pp.70-75
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    • 1992
  • As new city apartment construction of five brought about the short of the domestic output rocal construction materials , therefore the construction materials have been in part imported from foreign, here it is important that it is ensured the warranty of the quality for the construction materials lacking K.S. mark. Therefore in this research, we are trying to grasp the degree of strength of the concrete made as the cement from china and the intensity power of the estimate for the quality of construction materials and the guide in making a construction.

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PSC 교량 부재의 시공이음부의 극한 휨강도 평가 (Ultimate Flexural Strength Evaluation of Construction Joints in PSC Bridge Girders)

  • 채성태;오병환;김병석;이상희
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.279-284
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    • 2002
  • Prestressed concrete(PSC) bridge structures with a number of continuous spans has been segmentally built in many countries. These methods include incremental launching method, movable scaffolding method, full staging method and balanced cantilever method. In these segmentally constructed prestressed concrete bridges, many construction joints exist and these construction joints are weak points in PSC bridges. The prestress force can be introduced prestress force continuously through the construction joints of PSC bridge superstructure using tendon couplers. The main objective of this study is to evaluate the structural behavior and ultimate flexural strength of construction joints in PSC girder bridge members. To this end, a comprehensive experimental program has been set up and a series of full-scale tests have been performed. Ultimate flexural strength of construction joint in PSC members with tendon couplers is decreased by approximately 10% for non-coupled members.

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Multiple Regression Technique for Productivity Analysis of the Jointed Plane Concrete Pavement (JPCP)

  • Yoo, Wi-Sung
    • 한국건설관리학회논문집
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    • 제9권6호
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    • pp.268-276
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    • 2008
  • In highway construction projects, concrete pavement productivity has been challenged with constructors and decision-makers; at present there are few methods available to accurately evaluate the factors impacting on it. Any inefficient method to analyze it leads to the excessive schedule, higher rehabilitation costs, shorter service life, and reduction of ride quality. To implement these negative outcomes, constructors or decision-makers need a systematic tool that can be used to categorize the factors related to construction productivity. This paper applies multiple regression technique for productivity analysis of the Jointed Plane Concrete Pavement (JPCP), identifies the significant factors, and provides a predictive model assisting in monitoring and managing the productivity of the JPCP construction process. The completed and progressive projects are employed to derive and assess the proposed model. The results are analyzed to illustrate its capabilities.

ACCELERATED CONSTRUCTION OF URBAN INTERSECTIONS WITH PORTLAND CEMENT CONCRETE PAVEMENT (PCCP)

  • Kamran M. Nemati
    • 국제학술발표논문집
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    • The 1th International Conference on Construction Engineering and Project Management
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    • pp.886-891
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    • 2005
  • The frequent maintenance required on some asphalt concrete (AC) pavement sections has made reconstruction with Portland Cement Concrete Pavement (PCCP) a feasible alternative. However, many constructability issues need to be addressed in order to realize the full potential of this alternative. Accelerated paving encompasses three classes of activities: methods to accelerate the rate of strength gain, methods to minimize the construction time, and traffic control strategies to minimize user delay. Three major AC intersections with severe rutting problems were reconstructed with PCCP. The entire reconstruction of each intersection, including demolition of the AC pavement and its replacement with PCCP, took place over a period of three days, starting on Thursday evening and opening the intersection to the traffic on Sunday afternoon. This paper discusses the use of PCCP for accelerated reconstruction of major urban intersections with minimal user and traffic disruption, using innovative construction techniques and traffic management optimization principles and demonstrates that concrete pavements can be constructed efficiently and quickly.

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규사를 폐콘크리트 미분말로 대체한 PHC 파일용 콘크리트의 강도특성 (Strength of concrete for PHC pile Replacing the silica to Waste Concrete Powder)

  • 서은석;정의인;김봉주
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.9-10
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    • 2015
  • Waste Concrete Powder will be generated during the manufacture of construction waste as recycled aggregate Waste concrete. The main component of the waste concrete Powder is a silica-based composition 51% SiO2, waste concrete cement-based composition Al2O3 10%, CaO 26% component are contained. The material is silica sand of PHC piles should experiment by replacing the Waste Concrete Powder. The compressive strength results are as follows. 25% when the Silica was replaced 32.5Mpa, when 50% have replaced 43.4Mpa, when 75% have replaced 45.3Mpa was measured. Compared with the non-replaced test sample it appears that the strength increases. Therefore, it is determined that the practical use of the PHC piles by replacing silica via this experiment is possible.

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시트양생 및 파이프 쿨링에 의한 매스콘크리트 구조물의 온도제어 (Temperature Control of Mass-Concrete Structure with Pipe Cooling or Sheet Curing.)

  • 차홍윤;김은경;김래현;신치범
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.263-267
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    • 1995
  • The usual methods for the temperature control of mass-concrete structures include the use of low-heat cement, pre-cooling, post-cooling, or sheet curing. In order to control the heat of hydration during the construction of mass-concrete structures, the combination of the above methods is commonly employed. For the construction of mass-concrete structures such as massive pier or anchor, it is necessary to control the curing temperature with pipe cooling. In this study, the method of analysis on the effect of pipe of was proposed to prevent the thermal cracking due to heat of hydration In addition the effect of covering the concrete surface with blanket insulation was investigated. The results of the present study may be useful for the prediction of curing temperature of mass-concrete structures and the reasonable construction management.

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수화열을 고려한 터널 라이닝 콘크리트 거푸집 탈형 (The Application of Hydration Heat to Form Removal of Lining Concrete in Tunnel)

  • 이종길;정형목;김국한;남궁영환;박찬규
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.347-350
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    • 2005
  • The strength level for removal of lining concrete in tunnel is increased from 2.94MPa to 4.9MPa in 2004. This result in the increase of concrete curing time, and construction time would be delayed. In this study, in order to improve the efficiency of construction cycle and satisfy the strength criterion, a curing method is adopted, which is considering the hydration heat in the lining concrete member. As a result, it is shown that the concrete curing time for form removal is about 20hrs without the adjustment of concrete mix design. And construction cycle time is not changed compared to that before the change of strength criterion.

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비정형 콘크리트 부재 생산을 위한 주조기술 개발 (Development of Casting Technology for Freeform Concrete Segments)

  • 김경주;이동훈;김선국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.66-67
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    • 2014
  • Design and construction of freeform building technologies are being implemented to reduce time and cost due to the development of materials and equipments. However, production of freeform concrete segments takes much more time and manpower than typical due to disposable mold and various shape. Therefore, manufacturing technology of freeform concrete segments need to be developed for securing economic and constructive feasibility. The objective of this study is development of efficient casting technology for freeform concrete segments in a short time. This technology includes details about the fluidity of concrete and the sectional shape of freeform concrete segments. And problem of cost and time can be solved. Also, mold can be reusable and freeform concrete segments will be produced quickly and accurately. After this study, productivity study for validation will continue through prototype development and example application.

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$23,000m^3$ 대용량 바닥스래브 콘크리트의 시공기술 (Construction technology of the massive bottom slab placed by $23,000m^3$ concrete quantity)

  • 권영호;이현호;하재담
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.1035-1040
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    • 2003
  • This research investigates the actual data and construction technology of the massive bottom slab placed by $23,000m^3$ concrete quantity in site of the in-ground type LNG receiving terminal having 20,000kl storage capacity. The purpose of this study is to determine the optimum mix design and control the actual concreting procedures including concrete production, transportation, placement, vibrating and curing in site. For this purpose, the optimum mix design using ternary blended cement(furnace slag cement+fly ash) and under piping method having 11 gates and 7 distributors are selected. As test results of actual construction, concrete placement is finished during 68hours with good success and obtained the good quality of the fresh and hardened concrete including slump, air contents, no-segregation, compressive strength and low hydration heat. Also, actual data for all of concrete procedures are proved successful and satisfied with our specifications.

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